Butterfly populations were monitored at two coastal locations in the lower Florida Keys to observe and evaluate their response to hurricane and tropical storm activity. Four major hurricanes--Dennis, ...Katrina, Rita and Wilma--occurred within the vicinity of the Florida Keys during 2005. The ocean-facing exterior portions of both study areas were heavily damaged by hurricane and tropical storm force winds, salt spray and storm surge, resulting in greatly reduced butterfly abundance and species richness. More interior portions of the study areas, while inundated with floodwaters, retained the majority of their vegetation throughout the storm season allowing for an assemblage of butterflies similar in richness, albeit reduced in abundance, to pre-storm conditions. At each study area butterfly recovery time appeared related to availability of appropriate host and nectar plant species. However, the decline, disappearance or slow recovery of certain butterflies suggests that storm activity had a deleterious influence on the natural histories of select butterflies.
Star formation in massive galaxies is quenched at some point during hierarchical mass assembly. To understand where and when the quenching processes takes place, the authors study the evolution of ...the total star formation rate per unit total halo mass ( capital sigma (SFR)/M) in three different mass scales: low mass halos , groups, and clusters, up to a redshift ... approximately 1.6. We use deep far-infrared PACS data at 100 and 160 mu m to accurately estimate the total star formation rate of the luminous infrared galaxy population of 9 clusters with mass similar to 10 super( 15) M..., and 9 groups/poor clusters with mass similar to 5 10 super( 13) M... The field capital sigma (SFR)/M increases with redshift up to ... similar to 1 and it is constant thereafter. The evolution of the capital sigma (SFR)/M - ... relation in galaxy systems is much faster than in the field. Up to redshift ... similar to 0.2, the field has a higher capital sigma (SFR)/M than galaxy groups and galaxy clusters.(ProQuest: ... denotes formulae/symbols omitted.)
The Florida leafwing, Anaea troglodyta floridalis F. Johnson and Comstock (Nymphalidae), occurs locally within the pine rocklands of southern Florida and the lower Florida Keys (Minno & Emmel 1993; ...Smith et al 1994). Hennessey and Habeck (1991) and Worth et al (1996) described many aspects of A. t. floridalis natural history. Salvato & Hennessey (2003) also discussed A. t. floridalis ecology and provided a review of known parasites and predators for the species. Although several larval parasites have been mentioned for Anaea Huebner (DeVries 1987) and similar genera (Muyshondt 1974a, 1974b; Caldas 1996) throughout tropical America, little has been reported for A. t. floridalis larvae.
Bars in early- and late-type discs in COSMOS Cameron, E.; Carollo, C. M.; Oesch, P. ...
Monthly notices of the Royal Astronomical Society,
11/2010, Letnik:
409, Številka:
1
Journal Article
Submillimeter galaxies (SMGs) represent a dust-obscured high-redshift population undergoing massive star formation activity. Their properties and space density have suggested that they may evolve ...into spheroidal galaxies residing in galaxy clusters. In this Letter, we report the discovery of compact ({approx}10''-20'') galaxy overdensities centered at the position of three SMGs detected with the Max-Planck millimeter bolometer camera in the COSMOS field. These associations are statistically significant. The photometric redshifts of galaxies in these structures are consistent with their associated SMGs; all of them are between z = 1.4and2.5, implying projected physical sizes of {approx}170 kpc for the overdensities. Our results suggest that about 30% of the radio-identified bright SMGs in that redshift range form in galaxy density peaks in the crucial epoch when most stars formed.
We analyze the morphological properties of a large sample of 1503 70 {mu}m selected galaxies in the COSMOS field spanning the redshift range 0.01 < z < 3.5 with a median redshift of 0.5 and an ...infrared luminosity range of 10{sup 8} < L{sub IR}(8 - 1000 {mu}m)< 10{sup 14} L{sub sun} with a median luminosity of 10{sup 11.4} L{sub sun}. In general, these galaxies are massive, with a stellar mass range of 10{sup 10}-10{sup 12} M{sub sun}, and luminous, with -25 < M{sub K} < -20. We find a strong correlation between the fraction of major mergers and L{sub IR}, with the fraction at the highest luminosity (L{sub IR} > 10{sup 12} L{sub sun}) being up to {approx}50%. We also find that the fraction of spirals drops dramatically with L{sub IR}. Minor mergers likely play a role in boosting the infrared luminosity for sources with low luminosities (L{sub IR} < 10{sup 11.5} L{sub sun}). The precise fraction of mergers in any given L{sub IR} bin varies by redshift due to sources at z > 1 being difficult to classify and subject to the effects of bandpass shifting; therefore, these numbers can only be considered lower limits. At z < 1, where the morphological classifications are most robust, major mergers clearly dominate the ULIRG population ({approx}50%-80%) and are important for the LIRG population ({approx}25%-40%). At z > 1, the fraction of major mergers is lower, but is at least 30%-40% for ULIRGs. In a comparison of our visual classifications with several automated classification techniques we find general agreement; however, the fraction of identified mergers is underestimated due to automated classification methods being sensitive to only certain timescales of a major merger. Although the general morphological trends agree with what has been observed for local (U)LIRGs, the fraction of major mergers is slightly lower than seen locally. This is in part due to the difficulty of identifying merger signatures at high redshift. The distribution of the U - V color of the galaxies in our sample peaks in the green valley ((U - V) = 1.1) with a large spread at bluer and redder colors and with the major mergers peaking more strongly in the green valley than the rest of the morphological classes. We argue that, given the number of major gas-rich mergers observed and the relatively short timescale that they would be observable in the (U)LIRG phase, it is plausible for the observed red sequence of massive ellipticals (<10{sup 12} M{sub sun}) to have been formed entirely by gas-rich major mergers.
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